The present invention relates to an improvement on the door liner and door assembly for a coke oven as described in my co-pending application, Ser. No. 932,884, the contents of which application are incorporated by reference herein.
As described in my said co-pending application, earlier attempts to provide a door plug that was spaced apart from the metal door in a coke oven door assembly resulted in problems of condensation of coking gases on the inside surface of the metal door and doorjambs, which condensed gases formed hard dense deposits that interfered with the seal between the metal door and the jambs, and which tended to plug the gas channel areas.
These problems were solved by use of the door liner and door assembly described and claimed in my said co-pending application, wherein first and second spaced refractory layers were provided, one on the cold side, or door side, of the assembly and the other on the hot side, or coke side, of the assembly. These layers were each constructed from a plurality of abutting, vertically aligned sections with the cold side refractory layer having a recess in the surface of the sections facing the door, in which an insulating material was disposed. With this assembly, gases entered on elongated chamber formed between the first and second refractory layers so as to rise to the top portion of the coke oven chamber without condensation occurring between the spaced refractory layers.
While the above-described door liner and door assembly was a distinct advance over prior art designs, under certain conditions various problems were encountered. One problem was associated with occasional overfilling the coke side top. Overfilled coal can be snow-plowed ahead of the leveler bar of the coke oven charging machine, with a resultant forcing of some coal over the coke side hot face refractory layer and such coal can find its way into the elongated chamber between the hot side refractory and cold side refractory layers. When such displaced coal becomes heated, gases are produced which are forced into the original gas channel area and condensed.
A further problem that was encountered under certain conditions was in connection with the bottommost refractory layer. Some of the coal which can enter through the top of the door, between the hot face and cold face refractory layers, can coke and cling to the oven hearth. When the door is pulled, for discharging of the oven, such coke clinging to the oven hearth can cause the bottommost hot face refractory section to hang up and possibly eventually crack that section.
A more consistent difficulty with the proposed door liner and assembly, however, was not the result of the construction thereof but rather the non-uniformity of the coke oven walls even in a single series of ovens. It has been found, in practice, that coke oven walls are very irregular and there is some difference in width of an oven from one oven to the next even within the same coke oven battery. With such a variation in oven widths, an ideally designed gap between one oven wall and the sides of the hot face refractories of my door might be, in some ovens either too wide or non-existent. A too wide of a gap permits coal to intrude through the gap to the gas exhaustion area provided between the two spaced refractory layers, which could cause the door to fail. On the other hand, if a sufficiently sized gap is not present, the door may be caused to stick during removal and this can cause refractory failing by cracking. Needless to say, the customer abhors the possibility of having to purchase a specific sized door for each oven in a battery, having various oven widths, with selective fitting of a particular door to a particular oven.
It is an object of the present invention to provide a coke oven door and liner that has spaced refractory layers which are suitable for use in coke ovens of non-uniform width, with a door adaptable for use in all coke oven chambers of a coke oven battery without modification due to varying widths of specific chambers in the battery.